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Type of variability: M

These are long-period variable
giants with characteristic late-type emission spectra (Me, Ce, Se) and
light amplitudes from 2.5 to 11 mag in V. Their periodicity is
well pronounced, and the periods lie in the range between 80 and
1000 days. Infrared amplitudes are usually less than in the
visible and may be <2.5 mag. For example, in the K band they
usually do not exceed 0.9 mag. If the amplitudes exceed 1 - 1.5
mag , but it is not certain that the true light amplitude exceeds 2.5
mag, the symbol "M" is followed by a colon, or the star is
attributed to the semiregular class with a colon following the
symbol for that type (SR).